Wet-splitting hot air dryer



Sept. 16, 1958 A. c. ADAMS WET-SPLITTING HOT AIR DRYER 2 Sheets-Sheet 1 Filed Oct. 22, 1954 GILL $22125;

Sept. 16, 1958 A. c. ADAMS WET-SPLITTING HOT AIR 'DRYER 2 Sheets-Sheet 2 Filed Oct. 22, 1954 WW 2 m 3 H. n hm Q a u I. mm .m R a m o m m om MM m mm M; Uh U I w w w 6 x x m x United States Patent WET-SPLITTING HOT AIR DRYER Andrew C. Adams, Saco, Maine, assignor to Saco-Lowell Shops, Boston, Mass., a corporation of Maine Application October 22, 1954, Serial No. 463,950

7 Claims. (Cl. 28-28) This invention relates to textile yarn treatment and more particularly to novel slashers of the wet-splitting type, together with novel methods employed therein.

The principal purpose of slashing is to impart to the yarns of a warp sufiicientresiliency and abrasion resistance to withstand the tensions and chafingaction to which the warp is subjected in looms. Slashing attempts to do this by building around and causing to penetrate into each of the yarns a protective coating of size. If the coating is defective in amount of penetration or .continuity, there will be exposed sections of yarn beingtrun through the loom. Such exposed sections are easily chafed, resulting in warp breaks which necessitate stopping the loom and retying the broken ends.

The typical method of slashing as commercially practised heretofore has been essentially the same as that in use at the inception of mechanical slashing. Briefly, the sequence of operations on the mass of yarn through the prior commercial slashing apparatus was as follows: the

section beams, generally of the order of 1.0 or .12, were placed on a creel located at the input end of the .slasher. The yarn ends on the last beam were picked up, carried to and combined with the ends on the next preceding beams until the ends of all the section beams were com- .ing the warp were then brought together at the comb and wound on the loom beam at the output end-the head end- -of the slasher.

Patented Sept. 16,1958

plurality of sheets preferably corresponding in number :to the number of section beams, drying the split yarn :in open condition in a suitably dryer such as a hot air drier to provide uniformly starch coated substantially rod-like yarns, and finally reassembling the dried yarn ends'and winding them on a beam.

I have found, however, that it is not at all essential to separate the yarn mass during the initial drying thereof, as has heretofore been thought to be the case. On the contrary, I have discovered that it is entirely practical initially to dry the assembled mass of yarn to a considerable extent before opening the yarn sheet. Accordingly .I first apply heat and thereby partially dry the yarn mass to reduce its moisture content to about then open the partially dried and heated mass while it is still wet and continue drying the yarns in separated condition until their moisture content is reduced to about 20% By such novel method, I am enabled to provide a slasher having a novel wet-splitting hot air dryer, which .dryer operates to first ,heat and thereby partially dry the yarn ends in assembledcondition, next to open the yarn mass and continue the drying to a non-tacky condition, and finally to reassemble the non-tacky yarn ends for further drying.

Itis a particular feature of my invention that its use provides a substantially more compact and simpler slasher structure than with heretofore known wet-splitting,'hot air drying Slashers, since my novel dryer in effect replaces both the wet-splitting unit and drying unit as heretofore used. Furthermore, the various means heretofore found necessary to prevent yarn sticking and tangling, particularly in the wet-splitting unit, appear to be unnecessary with my novel dryer.

It is .a further feature of my invention that novel means are provided for controlling the air velocity and air recirculation including the exhausting of moistureladen air from hot air dryer.

For the purpose of explaining further features of my 7 novel method of slashing and apparatus therefor, refer- With the current method of slashing as indicated above, 7

the yarn has been dried in one mass in which the individual ends adhered to one another. .Thus, at the head end, in order for the lease rods to separate the mass into sheets, each end was actually torn away from its adjacent ends, causing breaking up of the protective coat of starch as well as shedding (granules of starch dropping size could be in effect individually dried on each end.

Such a procedure would eliminate the problems of tearing of the size envelope by the lease rods at the head end and would thus providea smooth rod-like end which would be much less susceptible to breakage and shedding in the loom.

Various complicated means have been proposed for ence is 'made to the following drawings illustrating a preferred embodiment thereof, in which:

Fig. ,l is a diagrammatic side elevational view of the novel slasher of my invention;

Fig. 2 is a diagrammatic side elevational view of the novel wet-splitting hot air dryer of the slasher of ,Fig. l; and

Fig.3 is a circuit diagram of the control means of "the dryer of Fig. 2.

Referring now to Fig. l the wet-splitting hot air drying slasher of my invention includes a creel generally designated at 15?, a sizing mechanism generally designated at20,a-wet-splitting hot air dryer generally desig- ;'nated at 30, anda head end generally designated at 40. *Such components need not be "connected mechanically a-number of section-or creel beams 12, herein sixteen in number. Such creel is preferably-of the over and under type-in which the alternate beams are staggered inheight achieving this result, but the most practical approach to the problem has been by opening up or splitting the wet from the floor to minimize the overall length of the creel, particularly when a large number of creel beams are to be used *therein. In general, any conventional creel as ing or splitting the assembled yarn mass.

known to those in the art may be used with my novel around the second to last beam, picking up the yarns on the second to last beam and so on until the ends of all the beams have been picked up to form a composite assembled mass of yarn.

The yarns thus assembled are passed to a size vat generally designated 20, such size vat being of any suitable type known to the art. conventionally, and as shown, the size vat 20 includes a tank 22 containing a sizing solution, said tank having mounted therein beneath the surface of said solution a roll 24 around which the yarns are passed to impregnate them with size solution. Pairs of squeeze rolls 26 and 28 are provided to squeeze the excess size solution from the yarn mass. Starch solutions are preferably employed as sizing solutions, but other types of sizing solutions can also be used.

From the sizing mechanism, the assembled mass of yarns impregnated with sizing solution, passes directly to my novel wet-splitting hot air dryer, generally indicated at 30, and hereinafter more fully explained. Such dryer in general includes, within an insulated enclosure, an upper pair of plenum chambers 32 and 34 forming a first yarn passage between their opposed air distributing surfaces, and a lower pair of plenum chambers 36 and 38 spaced therefrom similarly forming a third yarn passage, the second yarn passage between said pairs of plenum chambers having mounted therein means for separat- The dryer is operated to maintain a high temperature during the first pass of the yarn mass therethrough so that the moisture content of such yarns will be reduced to about 50% without, however, drying them to a tacky condition i. e., they will still be wet. In the second pass, the yarn mass is separated or opened and a suitable temperature is maintained so that the yarns thereof will be dried beyond the tacky stage before they are reassembled. After reassembling at the end of the second pass, drying is continued through the third pass to any desired final moisture content. Carrier rolls 33 and 35 are provided at the ends of the first and second passes, respectively, so that i said passes may be arranged in vertical relation to keep the overall length of the wet-splitting dryer structure relatively short.

From the dryer 30, the dried assembled yarn ends pass to the head end, generally indicated at 40, such head end being of any conventional type as known in the art for winding up the assembled sheet of yarns onto a loom beam. As shown, the head end 40 has a frame 42 on which is mounted a warp beam 44 which may be driven by a suitable motor (not shown), such head end being provided with delivery and press rolls 45, 46 and 47, as well as lease rods 49 and a comb 48. With my novel slasher, however, it is not necessary to split the yarns at the lease rods on such head since the splitting takes place before the yarns are dried.

The mass of yarns is driven through the slasher in a conventional manner by suitable power drive means comprising, for example, three motors (not shown), a sizing mechanism motor, and two head end motors. As is known in this art, it is essential to arrange such motors so that they may be stopped and started without appreciably varying the tension on the sheet of yarn and that they, while running, maintain a substantially uniform tension.

My novel wet-splitting hot air dryer 30, as best shown in Fig. 2, is positioned immediately following the sizing mechanism 20 in order to dry the yarns which have been sized thereby so that they may be wound on a loom beam by the head end 40. The hot air dryer, as pointed out above, has three separate yarn passes, the first and third of which have their own individual air recirculating and heating means for maintaining them at different temperatures for most effective drying as hereinafter more fully explained.

In general, the dryer includes a frame 50 having mounted therein two pairs of plenum chambers spaced one above the other, the entire dryer preferably being enclosed within insulating surfaces 52 having suitable openings for the passage of yarns into and out of the dryer. The upper pair of said plenum chambers is mounted horizontally in said enclosure with the working faces of said chambers opposed, and provides air distributing means for the first pass of the dryer. The upper plenum chamber 32 of said pair is mounted adjacent the top of the enclosure, and the lower plenum chamber 34 of said upper pair is mounted below in opposed spaced relation from upper plenum chamber 32, the space between said chambers thus forming a first horizontal passage for the mass of yarns M entering the dryer through opening 54 therein from the sizing mechanism 20.

The lower pair of plenum chambers 36 and 38 is mounted and arranged similarly to the upper pair, but with the upper plenum chamber 36 thereof immediately below and spaced from lower plenum chamber 34 of the upper pair at a substantial distance, as hereinafter explained, to form the second pass for the yarn ends. A

1 first carrier roll 33 is provided mounted on frame 50 at the end of the first pass of the dryer opposite to the sizing mechanism 20, such roll being of a diameter sufiicient to guide the yarns from the space between upper plenum chambers 32 and 34 into the space between the upper and lower pairs of plenum chambers, and a second carrier roll is similarly arranged to guide the sheet of yarns passing between plenum chambers 34 and 36 into the third pass between the lower pair of plenum chambers. A guide roll 56 is provided at the end of said third pass, such roll being adjacent an opening 58 in the enclosure to allow the passage of the dried assembled sheet of yarns out of the dryer 30 to the head end 40.

The plenum chambers 32, 34, 36, and 38 forming the hot air distributing means, are all identical in construction and include generally rectangular enclosures having horizontal outer operating surfaces adjacent the first and third yarn passes. Such operating surfaces include a plurality of members 60 forming louvers 62 extending transversely of the apparatus, the louvers forming openings which are narrowest at the operating surface and expand inwardly toward said enclosure. The members extending between said louvers are fiat on the operating surface and smoothly rounded at their interior surface. Such an opening provides a smooth non-turbulent air flow which is most effective in its drying action of the yarns passing and spaced from said surface. To provide generally uniform air flow within the plenum chamber itself so that each louver is provided with air at the 7 same pressure, the top and bottom surfaces of said chambers are constructed closer together at the end opposite the input ends of such chamber.

Each of the pairs of plenum chambers is provided with separate heater and blower systems driven by suitable motors 71 and 81 as is well understood in the art.

Thus, the upper pair of plenum chambers 32 and 34 has a heater and blower driven by motor 71 (Fig. 3), said heater and blower having an output duct 72 connected to said plenum chambers and a return duct 74 from the said heater and blower.

end of the first pass back to said heater and blower. Lower plenum chambers 36' and 38 are provided with a heater and blower driven by motor 81 (Fig. 3) andhave an output duct 82 for providing heated air to said plenum chambers, a return duct 84 being provided to return the air from the end of the third pass back to Preferably, preheaters 59 are provided adjacent the exit opening 58 for preheating the atmosphere air supplied to heater and blower 80, the

Iflow of air through such preheaters also aiding in cooling the yarn as it passes from the hot air dryer.

Novel means are provided for controlling the dryer by exhausting moisture laden air from the first pass of the dryer and for intake of fresh air into the third pass as well as for providing movementof air through the yarn in the second pass as air is exhausted from the first pass. Accordingly, an exhaust duct 90 havingan exhaust fan .92 is provided connected to first yarn pass air return duct 74, said fan being operated by a suitable motor 93. As shown in Fig. 3, the blower motors 71 and 81 and the exhaust fan motor 93 are all direct current motors connected to a suitable source of power at terminals 88, a common controlling rheostat 86 being .provided for controlling all of such motors and an additional controlling rheostat 95 being provided in series with said rheostat 86' for controlling exhaust fan motor 93. Thus, when the heaters and blowers are operating, the exhaust fan 92 removes the moisture-laden air from the first pass, air is caused to flow through the second pass between the heat-radiating surfaces of plenum chambers 34 and 36, and air is drawn into the third pass through preheaters 59. The ratio of air exhausted by fan .92 to air recirculated within the first and third passes is determined by the setting of fan motor rheostat 95. The setting of the common rheostat 86 determines the recirculating air velocity within'the first and third passes, while maintaining said ratio constant.

The Wet-splitting means of rny novel dryer, as best shown in Fig. 2 is arranged in the second yarn ,pass between the spaced surfaces of the upper and lower pairs of plenum chambers, and first separates into two sheets the heated and partially dried mass of yarn as .it comes from the first dryer pass in wet, non-tacky-condition. These two sheets are then further separated into a plurality of sheets corresponding preferably to the number of beams in the creel, herein shown as sixteen. .Tshe thus separated yarns, since their moisture content during such separation is high enough to prevent their adhering to one another, have a smooth size coating thereon and are further dried individually out of contact with one another until they reach a non-tacky condition to give a smooth rod-like structure without protruding fibers. The heat is provided in the second pass both by radiation from the surfaces of plenum chambers 34 and 36 and by the flow of heated air through the separated yarns in said pass.

The wet-splitting mechanism itself includes two pairs of rotatable lease rods 96 mounted on frame 5.0 on 'opposite sides of the second yarn pass adjacent the bottom and top surfaces ofplenum chambers 34 and 36, respectively, for initially separating into four portions the sheet of yarn as it comes from the first pass. Following the lease rods are mounted on said frame a series of rotatable wet-splitting rolls 98, herein shown as fourteen in number.

The wet-splitting rolls 98 are mounted in two rows one above the other, the axes of the rolls of each row being substantially parallel to one another and forming a plane. Such planes are somewhat tilted, the upper plane downwardly toward the input end of the second pass and the lower plane upwardly toward the input end of said pass so that the first pair of upper and lower rolls 98 are but a short distance apart, and such distance increases with each succeeding pair of rolls, the last pair of such rolls being about the same distance apart as are lease rods 96. The tilting of the rows of rolls 98 maintains each yarn sheet separate from those adjacent until all of them are reassembled at carrier roll 35.

The wet-splitting rolls 98, in order to maintain them free of starch accumulations, preferably have surfaces of a material to which starch or other sizing solutions will not adhere. A number of synthetic organic materials are known to have this property, but I have found that tetrafiuoroethylene resin, commonly known as Teflon, is particularly suitable, since by coating conventional steel rolls with such a material, no difficulty caused by size adhering to said rolls is experienced. Preferably, lease rods 96, carrier rolls 33 and 35, and guide roll 56 are also coated with Teflon. Other types of resins, such as certain silicone resins, are also suitable for coating lease rods 96, or such lease rods can be constructed entirely of such resins, if desired.

In operation, with a mass of yarns being moved from creel 10 through the starch solution in size tank 22 and wet-splitting dryer 30 as by slasher head end 40, and with heaters and blowers 70 and and exhaust fan 92 in operation, a mass of assembled yarns M impregnated with size is moved into the first pass of dryer 30 between the working faces of plenum chambers 32 and 34. During its movement through said first'pass, it is heated and partially dried thereby to reduce its moisture content about 50%, the yarn at this point still having enough moisture therein so that each end may easily be separated from those adjacent. The heated yarn mass is then .moved into the second pass between the surfaces of plenum chambers 34 and 36, where it is immediately separated by lease rods 96 and rolls 98. The heat retained by the yarns aided by the heat radiated by plenum chambers 34 and 36 and the heated air passing therethrough then causes further drying thereof while they are maintained in separated condition, so that said yarns will be dried to reduce their moisture content to about 20% so that they will be in a substantially non-tacky condition as independent, dried yarn ends by the time they are reassembled at carrier roll 35 at the .end of the second pass. The yarns are finally moved into the third pass where they may be further dried to any desired moisture content by plenum chambers 36 and 38.

Since the air flow through the dryer is counter-current to thedirection of yarn travel in that air is progressively moved from the third pass back to the first pass, gathering an increasing amount of moisture as it dries the yarns, finally being exhausted from the first pass after it has taken up its maximum amount of moisture, the yarns as they enter the first pass from the sizing mechanism are in their wettest condition. Hence, relatively high temperatures may be used in drying them in the first pass so that .the separated yarns in the second pass are readily dried beyond the tacky stage before they are assembled. Thus, with cotton yarns, for example, the temperature maintained in the first pass may be as high as 300 F. Without danger of damage to the yarn. The third pass is maintained at'lower temperatures, for example, if the first pass is maintained at 300 F., the third pass may be maintained at 250 F. When the slasher is running, a portion of the air being recirculated in the third pass will continuously be drawn through the second pass into heater and blower mechanism 70 and heated to a higher temperature with a consequent increase in its drying capacity. A portion of the air being recirculated in the first pass will be continuously removed by the exhaust fan, the amount of such portion being determined by the setting of exhaust fan rheostat 95, while the velocity of the air within the first and third yarn passes is determined by the setting of rheostat 86, and velocity of the air in the second pass is determined by the setting of said rheostat 95. The ratio between exhaust fan speed and blower speed is automatically retained when the velocity of the air is changed by resetting rheostat 86, since said rheostat is common to the fan and blower motors, and thus ratio of air recirculated to air exhausted will remain constant until rheostat be reset.

Thus it will be seen that I have provided a novel wetsplitting slasher and method, including a novel hot air dryer having wet-splitting means therein and control means therefor. It will be apparent to those skilled in the art that various modifications may be made within the spirit of my invention and the scope of the appended claims.

What is claimed is:

1. A wet-splitting hot air dryer for continuously drying an extended mass of yarn ends comprising, a first pair of plenum chambers providing a first yarn pass therebetween, a second pair of plenum chambers providing a third yarn pass therebetween, said chambers being mounted in vertically spaced relation to one another to provide a second yarn pass, a plurality of wet-splitting rolls mounted between said pairs of plenum chambers in said second yarn pass adjacent one end thereof for separating said mass of yarn ends into a plurality of sheets, a first carrier means for moving a yarn mass from one end of said first pair of plenum chambers to said wetsplitting rolls at one end of said second pass, and a second carrier means for reassembling said sheets into a mass of yarn ends and for moving said mass from the other end of said second pass to said third pass.

2. A dryer as claimed in claim 1 wherein said wetsplitting rolls have surfaces of tetrafluoroethylene resin.

3. A dryer as claimed in claim 1, in which each of said pairs of plenum chambers have opposed working faces comprising a plurality of transversely extending spaced members providing a plurality of louvers.

4. A hot air dryer for continuously drying an extended mass of yarn ends comprising a dryer enclosure, air distributing means in said enclosure for drying said yarn ends, heater and blower means for providing heated air to said distributing means and for recirculating a portion of said heated air from said air distributing means, exhaust fan means for continuously exhausting a portion of said recirculating air from said enclosure, and control means for said heater and blower means and exhaust fan means for varying the ratio between exhausted air' and recirculated air and for varying the velocity of the air being recirculated while maintaining said ratio substantially constant, said heater and blower means 'and said exhaust fan means each being provided with direct current motor means, and said control means including first rheostat means in series with said exhaust fan motor means, and second rheostat means in series with both said heater and blower means and the circuit consisting of said first rheostat means in series with said exhaust fan motor means. I

5. A wet-splitting hot air dryer for continuously drying an extended mass of yarn ends comprising a dryer enclosure, a first pair of plenum chambers mounted within said enclosure providing a first yarn pass therebetween, a second pair of plenum chambers providing a third yarn pass therebetween, said second pair of plenum chambers being mounted within said enclosure in vertically spaced relation to said first pair of plenum chambers to provide a second yarn pass, heater and blower means for providing heated air to said plenum chambers, exhaust fan means for exhausting air from said first pass, a plurality of wet-splitting rolls mounted within said enclosure between said pairs of plenum chambers in said second yarn pass adjacent one end thereof for separating said mass of yarn ends into a plurality of sheets, a first carrier means mounted within said enclosure for moving a yarn mass from one end of said first pair of plenum chambers to said wet-spitting rolls at one end of said second pass, and a second carrier means for reassembling said sheets into a mass of yarn ends and for moving said mass from the other end of said second pass to said third pass.

6. A wet-splitting hot air dryer for continuously drying an extended mass of yarn ends comprising a first pair of plenum chambers providing a first yarn pass therebetween, a second pair of plenum chambers providing a third yarn pass therebetween, said chambers being mounted in spaced relation to one another to provide a second yarn pass, a plurality of wet-splitting rolls mounted between said pairs of plenum chambers in said second yarn pass adjacent one end thereof for separating said mass of yarn ends into a plurality of sheets, a first carrier means for moving a yarn mass from one end of said first pair of plenum chambers to said wet-splitting rolls at one end of said second pass, and a second carrier means for reassembling said sheets into a mass of yarn ends and for moving said mass from the other end of said second pass to said third pass.

7. A wet-splitting hot air dryer for continuously drying an extended mass of yarn ends comprising a first pair of plenum chambers providing a first yarn pass therebetween, a second pair of plenum chambers providing a third yarn pass therebetween, a plurality of wet-splitting rolls I mounted between said pairs of plenum chambers providing a second yarn pass for separating said mass of yarn ends into a plurality of sheets, and carrier means for reassembling said sheets into a mass of yarn ends, and for moving said mass from the other end of said second pass to said third pass.

References Cited in the file of this patent UNITED STATES PATENTS 2,108,188 Batchelder Feb. 15, 1938 2,263,547 Harris Nov. 18, 1941 2,402,652 Martin June 25, 1946 2,679,086 Andrews May 25, 1954 2,700,203 Nimmons Jan. 25, 1955 

